docs: def annual_heating_design_day_990(self):
          """A design day object representing the annual 99.0% heating design day."""
          self._load_header_check()
          if bool(self._heating_dict) is True:
              avg_press = self.atmospheric_station_pressure.average
              avg_press = None if avg_press == 999999 else avg_press
              return DesignDay.from_ashrae_dict_heating(
                  self._heating_dict, self.location, True, avg_press)
          else:
              return None